Closure for sheet-metal container openings



Nov. 19, .1946. H. w. DODSON 2,411,149

CLOSURE FOR SHEET-METAL CONTAINER OPENINGS Original Filed July 20, 1939 2 Sheets-Sheet 1 u V 1 n r A V n 1N VEN TOR; HOWARDW Doosou A ORNEY,

Nov. 19, 1946. H. w. DODSON 2,411,149

CLOSURE FOR SHEET-METAL CONTAINER OPENINGS Original Filed July 20, 1939 2 Sheets-Sheet 2 INVENTOR. HOWARD V D0050:

A ORNEY.

Patented Nov. 19, 1946 CLOSURE FOR SHEET-lVlETAL CONTAINER OPENINGS Howard W. Dodson, Philadelphia, Pa., assignor to United Steel Barrel Company, Philadelphia, Pa., a corporation of Pennsylvania Original application July 20, 1939, Serial No. 285,477. Divided and this application August 12, 1943, Serial No. 498,289

1 Claim. (Cl. 22039) The present invention relates to certain new and useful closures for sheet-metal containers such as steel drums and the like, and it relates more particularly to certain constructions in the openings and the closures therefor whereby said steel or other sheet metal containers may be emptied and refilled.

For the purpose of illustrating the invention, there are shown in the accompanying drawings forms thereof which are at present preferred, since the same have been found in practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which the invention consists can be variously arranged and organized and that the invention is not limited to the precise arrange ment and organization of the instrumentalities as herein shown and described.

The present application is a division of my application Serial No. 285,477, filed July 20, 1939, which issued into Patent 2,343,286, on March 7, 1944.

In the accompanying drawings, in which like reference characters indicate like parts,

Figure 1 represents a cross-sectional perspective view of one form of construction embodying the present invention.

Figure 2 represents a fragmentary cross-sectional perspective view of the container of Figure 1 as it appears in an intermediate stage of construction.

Figure 3 represents a cross-sectional perspective view of another embodiment of the present invention.

Figure 4 represents a fragmentary cross-sectional perspective view of still another form of construction embodying the present invention.

Figure 5 represents a cross-sectional perspective view of still another form of construction embodying the present invention.

Figure 6 represents a sectional perspective view showing another embodiment of the present invention.

Figure '7 represents a sectional perspective view of still another embodiment of the present invention.

Figure 8 represents a sectional perspective view of a further embodiment of the present invention.

In the drawings, only a fragmentary portion of one of the sheet-metal walls of the sheet-metal container is shown; it being understood that this sheet-metal wall is generally an end wall of a more or less cylindrical container, although it may be a side wall also. The sheet-metal wall r of the container is designated generally 'by the numeral 20 in all the figures.

In the embodiment of the invention shown in Figure 1, the sheet metal of the wall 20 is provided with a suitable hole, and the sheet metal is then flanged inwardly around the hole as shown in Figure 2 to provide. a more or less cylindrical flange 2| formed integrally with the sheet metal of the wall 20. Intermediate the more or less cylindrical flange 2| and the main body portion 20, the sheet metal is also preferably provided with a generally annular rib-like depression 22 or elevation 23 (in the form of construction shown in Figure 1, it is in the form of a depression while in the form of construction shown in Figure 3, it is an elevation). A generally flat annular gasket-seat 24 surrounds the flange 2| in the embodiment of Figure 1 while a generally flat annular gasket-seat 36 surrounds the flange 2| in the embodiment of Figures 3 and 4.

The annular ribs 22 and 23 serve as a stiflfening reinforcement around the opening defined by the generally cylindrical flange 2| and also around the generally flat annular gasket-seat 24 which surrounds the generally annular flange 2| in the embodiment of Figure 1 or around the flange-base portions 25 in the forms of construction shown in Figures 3 and 5; all the above named portions, namely the flange 2|, the gasketseat 24 and the reinforcing ribs 22 or 23 and flange-base 25, being formed integrally with each other and drawn or pressed out of the same metal as that of which the body 20 is formed. The sheet metal 20 may beof 12 to 26 gauge sheet-steel.

The flange 2| is then threaded by means of two or more coacting thread-forming rolls (of the form well known in the art) by means of which the metal of the flange 2|, which is initially in the form shown in Figure 2, is de-iormed in such a way that a thread 26 of the character shown in Figure 1 is produced. This thread (26) differs essentially from the rounded-cross-section thread commonly rolled onto the discharge spout of tin cans, in that the rolled thread on tin canned flanges is produced merely by bending the sheet metal, whereas the thread 26 hereinabove indicated is produced by an actual deformation or flowing of the comparatively heavy gauged sheetsteel under the pressure of the thread-forming 3 I sheet metal is provided with a cast thread or ,with a cut thread 33 as in Figure l and with a rolled thread 34 ,as in Figures 3, 4, 5, 6, 7 and 8 (formed in the same manner as the thread 28), corresponding generally to the thread 28 of the flange 2|, and having a laterally extending flange 35, in juxtaposition to the gasket-seats 24 and 38 and adapted to engage the annular sealing gasket 31 between itself and the gasket-seats 24 and 36, respectively, so as to form a fluidtight seal. The cavity 33 in the plug 21 may be of any suitable non-circular cross-section, as for instance, square, hexagonal, or triangular, for the reception of a wrench or other instrument by means of which the plug may be turned.

In the form of construction shown-in Figure 1, the annular wall. portion 45 of the annular reinforcing rib 22 (that is, the portion of the sheetmetal wall directly adjacent to the gasket-seat 24) is turned or formed or spun inwardly slightly so as to form a shoulder against which the flange 46 of a thin sheet-metal tamper-proofing cap 34 may be crimped inwardly, so as to prevent the removal of the plug 21 without detection.

In the embodiment of the invention shown in Figures 3 and 4, the annular reinforcing bead or rib 23 is raised upwardly intermediate the main body portion 23 of the sheet-metal wall of .the container and the annular portion 25 which forms a base for the upwardly extended bungflange 2| in the form of construction shown in Figures 3 and 4 (and also for the form of construction shown in Figure 6).

The bung-flange 2|, in the forms of construction shown in Figures 3 and 6, is extended upwardly from the basal portion 25, and can be terminated in a more or less sharp or flattened edge 36 constituting a gasket-seat as in Figures 3, 6 and 7.

. It should be understood the the screw-thread on the bung-flange 2|, in each of the modifications shownin Figures 3, 4, 5, 6, 7 and 8, is formed in the same manner as hereinabove indicated with respect to Figures 1 and 2, namely, by deformation or swaging the metal into the screw-thread formation.

The pressed or stamped sheet-metal plugs 28, 29, 30, 3| and 32 are formed in generally cup shape; the plugs 28, 29, 3| and 32 being cupped generally downwardly while the plug 30 is cupped generally upwardly. A transverse rib 48 may be pressed out of the central or more or less flat'portion of the cup-shaped plugs 28, 29 and 30, either extending entirely across the diameter thereof, or extending only across a part of the diameter thereof, whereby the plug may be engaged by a suitable tool such as a wrench, pliers or the like, or as in the case of the rib 49 in Figure 6, it may be engaged by any flat object such as a wide screw driver or any flat piece of metal. If desired, a solid metallic rib 50 may be extended across the flat part of the plug and spot-welded thereto or otherwise secured thereto, for the same purpose as in the plug 32 of Figure 7.

The plugs 28, 29, 30 and 32 may also be provided with gasket-confining flanges, as for instance, the annular flanges shown in Figures 3 and 5, or by the inwardly crimped flange 53- shown in Figure 'l, or, as in the case of the type of plug 30 shown in Figure 6, the central part of the plug may be depressed to form the inner gasket-confining flange 54; By this means, the gasket 31 is not only confined in a generally axial direction, but is also confined in a generally radial the container.

direction so as to prevent its spreading unduly and thereby loosening the see-1;

The relationship of the gasket-confining flanges BI and 53 might be either that indicated in Figures 3 and 7, where the flange extends below the gasket-seat 24 or 38, or it may be that illustrated in Figure5 where it extends only down to the depth of the gasket 31. The gasket-confining flanges may also be provided on the cast plugs, such as the cast plugs 21 indicated in Figure 1, by merely extending the cast metal portions downwardly, that is, by extending a downward gasket-confining flange from the lateral flange 33 at a diametral point just sufllcient to clear the outer diameter of the gasket 31.

In the form of construction shown in Figure 6, the axial distance or axial extent of bung-flange 2| and of the threaded portion of the plug may be so related or proportioned as to be substantially equal, thereby permitting the interposition of a second sealing gasket 55 between the lower periphery of the threaded portion 34 of the plug and the flange-base 'portion2i, as indicated in Figure 6.

The tamper-resistant cap 58, shown in Figure 3, may be crimped inwardly against the outer surface of the threaded flange 2| as at 51. As shown in Figure 3, the cap 56 (which is of readily-deformable material such as very thin sheet metal or the like) is somewhat over-size relative to the bung 28 so that an annular radial clearance is provided therebetween; it being impossible to remove the cap 58 from about the bung opening without substantial deformation of said cap. In Figures 5 and 6, two further alternative forms of tamper-resistant cap arrangement are shown. In Figure 5, the tamper-resistant cap 58 is an outwardly flared skirt portion 59 which is adapted to be snapped into or to be spread out into the annular inwardly enlarged portion formed intermediate the inclined portion 8| and the main body portion 20 of the sheet metal of The tamper-resistant cup 62 shown in Figure 6 (likwise formed of thin sheet metal) is on the other hand provided with the inwardly crimped skirt 63 which is crimped around the undercut outer shoulder 64 of the raised rib 23.

In the form of construction shown in Figure 7,

the down-turned flange 53 of the plug is also threaded to engage one or more turns of the thread 28 of the bung-flange 2 In Figure 8, there is shown another embodiment of the present invention in which the stiffening rib 23 is pressed outwardly and surrounds the gasket-seat 24; the rib 23 serving radially to confine the gasket 31 when the latter is compressed by the shoulder 35 of the plug 29. The inwardly crimped skirt 83 of the tamper-resistant cap 62 is crimped around the undercut outer shoulder 34 of the rib 23 as in the embodiment of Figure 6.

It will be understood that the various features illustrated in the several figures of drawings may be interchanged with the corresponding features shown in modifications illustrated in other figures of the drawings.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiments be considered in all respects as illustrative and not restrictive, reference being had to the appended claim rather than to the foregoing description to indicate the scope of the invention.

Having thus described the invention, what I claim as new and desire to protect by Letters Patent is: In a sheet metal container, 9. generally cylindrical bung-flange drawn integrally from said container and defining an opening in a wall thereof, said bung-flange extending outwardly from said wall and providing a gasket seat at its outer 7 end, said bung-flange being helicaliy corrugated to provide an internal screw-thread and an external screw-thread thereon, an annular gasket disposed upon said gasket-seat, a screw-threaded bung operatively engaged with the internal screw- 

